Unit Plan 13 (Grade 6 Math): Writing & Interpreting Algebraic Expressions
6th graders learn to write and interpret algebraic expressions from verbal statements, identify parts like terms and coefficients, and evaluate expressions in real contexts. They use parentheses strategically, explain structure choices, and ensure results are precise and meaningful.
Focus: Write expressions from words, identify parts (terms, factors, coefficients), and evaluate in context.
Grade Level: 6
Subject Area: Mathematics (Expressions & Equations – Algebraic Expressions)
Total Unit Duration: 5 sessions (one week), 45-60 minutes per session
I. Introduction
This unit builds students’ fluency with algebraic expressions: turning verbal statements into symbolic expressions, naming the parts of an expression, and evaluating expressions by substituting values in real contexts. Emphasis: structure, precision, and reading expressions for meaning, not just calculation.
Essential Questions
- How do I translate words into a precise algebraic expression?
- What do the parts of an expression (for example, term, coefficient, factor, constant) tell me?
- When and how should I use parentheses/grouping symbols to match the meaning of a statement?
- How do I evaluate an expression and explain the reasonableness of the result in context?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Write expressions that represent operations with numbers and variables from verbal descriptions (for example, “five more than twice a number n” → 2n + 5).
- Identify and describe parts of an expression using precise terms (sum, term, product, factor, quotient, coefficient, constant) and treat a subexpression as a single entity (for example, see (3x + 2) as one factor in 4(3x + 2)).
- Evaluate expressions at given values (including negatives and zero) with correct order of operations and parentheses (for example, 3a^2 + 2b when a = -4, b = 5).
- Communicate choices of structure (why parentheses are needed, why a coefficient represents “times”) and check reasonableness in context.
- Diagnose and correct common errors (for example, confusing 2n with 2 + n, reversing phrases like “3 less than x,” or dropping parentheses in “twice the sum”).
Standards Alignment — CCSS Grade 6
- 6.EE.2a: Write expressions that record operations with numbers and letters for unknown quantities.
- 6.EE.2b: Identify parts of an expression using mathematical terms (sum, term, product, factor, quotient, coefficient); view one or more parts as a single entity.
- 6.EE.2c: Evaluate expressions at specific values; include those from formulas; follow the conventional order of operations when parentheses are absent.
- Mathematical Practices emphasized: MP.1 (make sense), MP.2 (quantitative reasoning), MP.3 (justify), MP.6 (precision), MP.7 (structure), MP.8 (regularity).
Success Criteria — Student Language
- I can write an algebraic expression that exactly matches a verbal description.
- I can name and highlight terms, factors, coefficients, and constants in an expression.
- I can use parentheses when needed (for example, “twice the sum” → 2(x + y)).
- I can substitute values and evaluate carefully with the correct order of operations.
- I can explain why my structure and result make sense in the real situation.